Kepong PKR information chief MS Arjunan was slashed several times on his face by one of the assailants who escaped with the other youth on the motorcycle.
“My father received four stitches on his face at a clinic in Bangsar,” said his son Kalaimughilan.
Arjunan and his son are expected to lodge a report at the Travers police station in Bangsar.
Earlier, Kalaimughilan and his father held a gathering at the Brickfields water fountain to raise money for the Sri Lankan Tamil refugees.
Kalaimughilan said he walked to a nearby restaurant to meet his friend when he heard his father screaming for help.
“I turned back and saw my father bleeding from the face. The assailant quickly sped off on the motorcycle before I could do anything,” he said.
Kalaimughilan claimed that the attack on his father could be politically motivated due to the latter’s work in championing the downtrodden.